Organic light emitting display apparatus

ABSTRACT

An organic light emitting display apparatus can include a substrate including a display area and a bending area; a pixel array layer including a driving wiring in the display area, and a thin film transistor electrically connected to the driving wiring; a planarization layer covering the pixel array layer; a light emitting device layer disposed on the planarization layer, the light emitting device layer being electrically connected to the thin film transistor; a routing wiring disposed in the bending area, the routing wiring being electrically connected to the driving wiring; a wiring contact part including a contact hole for electrically connecting the driving wiring to the routing wiring; and an encapsulation layer covering the light emitting device layer and the wiring contact part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of the Korean PatentApplication No. 10-2017-0125723 filed in the Republic of Korea on Sep.28, 2017, the entirety of which is hereby incorporated by reference asif fully set forth herein.

BACKGROUND Field of the Invention

The present disclosure relates to an organic light emitting displayapparatus.

Discussion of the Related Art

With the advancement of an information-oriented society, variousrequirements for display apparatuses for displaying an image areincreasing. Organic light emitting display apparatuses, which areself-emitting display apparatuses, have a wide viewing angle, anexcellent contrast, and a fast response time, and thus, are attractingmuch attention as next-generation display apparatuses. Recently, organiclight emitting display apparatuses are being released, which are evenslimmer. Flexible organic light emitting display apparatuses are easy tocarry and may be applied to various image display apparatuses.

Flexible organic light emitting display apparatuses each include abending area which enables a substrate to be folded. Since the substrateis folded in the bending area, a bezel size is reduced, and thus,organic light emitting display apparatuses having a narrow bezel may beimplemented.

However, as a degree of bending increases for realizing a more narrowbezel, a crack occurs in a routing wiring disposed in the bending area,causing a short circuit.

SUMMARY

Accordingly, the present disclosure is directed to an organic lightemitting display apparatus that substantially obviates one or moreproblems due to limitations and disadvantages of the related art.

An aspect of the present disclosure is directed to an organic lightemitting display apparatus which minimizes or prevents a crack at arouting wiring to enable easy bending, thereby protecting a lightemitting device from permeation of external water or moisture.

Additional advantages and features of the disclosure will be set forthin part in the description which follows and in part will becomeapparent to those having ordinary skill in the art upon examination ofthe following or may be learned from practice of the disclosure. Theobjectives and other advantages of the disclosure may be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the disclosure, as embodied and broadly described herein, there isprovided an organic light emitting display apparatus including asubstrate including a display area and a bending area, a pixel arraylayer including a driving wiring, including a gate line and a data linedisposed in the display area, and a thin film transistor connected tothe driving wiring, a planarization layer covering the pixel arraylayer, a light emitting device layer provided on the planarization layerand connected to the thin film transistor, a routing wiring disposed inthe bending area and connected to the driving wiring, a wiring contactpart including a contact hole electrically connecting the driving wiringto the routing wiring, and an encapsulation layer covering the lightemitting device layer and the wiring contact part.

Both the foregoing general description and the following detaileddescription of the present disclosure are explanatory and are intendedto provide examples and further explanation of the disclosure asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this application, illustrate embodiments of the disclosure andtogether with the description serve to explain principles of thedisclosure. In the drawings:

FIG. 1 is a plan view illustrating an organic light emitting displayapparatus according to an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view, taken along line I-I′ of FIG. 1,illustrating an organic light emitting display apparatus according to anembodiment of the present disclosure;

FIG. 3 is a cross-sectional view, taken along line I-I′ of FIG. 1,illustrating an organic light emitting display apparatus according toanother embodiment of the present disclosure; and

FIG. 4 is an enlarged view illustrating a structure of a bending area inan organic light emitting display apparatus according to an embodimentof the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

Reference will now be made in detail to embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

Advantages and features of the present disclosure, and implementationmethods thereof will be clarified through following embodimentsdescribed with reference to the accompanying drawings. The presentdisclosure may, however, be embodied in different forms and should notbe construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete, and will fully convey the scope of the present disclosureto those skilled in the art. Further, the present disclosure is onlydefined by the scopes of the claims.

A shape, a size, a ratio, an angle, and a number disclosed in thedrawings illustrating embodiments of the present disclosure are merelyan example, and thus, the present disclosure is not limited to theillustrated details. Like reference numerals refer to like elementsthroughout. In the following description, when the detailed descriptionof the relevant known function or configuration is determined tounnecessarily obscure the important point of the present disclosure, thedetailed description will be omitted.

When “comprise,” “have.” and “include described in the presentspecification are used, another part may be added unless “only” is used.The terms of a singular form may include plural forms unless referred tothe contrary.

In construing an element, the element is construed as including an errorrange although there is no explicit description.

In describing a position relationship, for example, when a positionrelation between two parts is described as “on,” “over,” “under,” and“next,” one or more other parts may be disposed between the two partsunless “just” or “direct” is used.

In describing a time relationship, for example, when the temporal orderis described as “after,” “subsequent,” “next,” and “before,” a situationwhich is not continuous may be included unless ‘just’ or ‘direct’ isused.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure.

A first horizontal axis direction, a second horizontal axis direction,and a vertical axis direction should not be construed as only ageometric relationship where a relationship therebetween is vertical,and may denote having a broader directionality within a scope whereelements of the present disclosure operate functionally.

The phrase “at least one” should be understood as including any and allcombinations of one or more of the associated listed items. For example,the meaning of “at least one of a first item, a second item, and a thirditem” denotes the combination of all items proposed from two or more ofthe first item, the second item, and the third item as well as the firstitem, the second item, or the third item.

Features of various embodiments of the present disclosure can bepartially or overall coupled to or combined with each other, and can bevariously inter-operated with each other and driven technically as thoseskilled in the art can sufficiently understand. The embodiments of thepresent disclosure may be performed independently from each other, ormay be performed together in co-dependent relationship.

Hereinafter, example embodiments of an organic light emitting displayapparatus according to an embodiment of the present disclosure will bedescribed in detail with reference to the accompanying drawings. In thespecification, in adding reference numerals for elements in eachdrawing, it should be noted that like reference numerals already used todenote like elements in other drawings are used for elements whereverpossible.

FIG. 1 is a plan view illustrating an organic light emitting displayapparatus according to an embodiment of the present disclosure.

Referring to FIG. 1, the organic light emitting display apparatusaccording to an embodiment of the present disclosure can include asubstrate 100, a driver 300, and a circuit board 400.

The substrate 100, as for a thin film transistor (TFT) array substrate,can be formed of glass, plastic, semiconductor and/or the like. Thesubstrate 100 according to an embodiment can include a display area AAand a non-display area IA.

The display area AA can be provided in a portion of the substrate 100,except for an edge of the substrate 100 (e.g., not along the outeredges). The display area AA can be defined as an area which displays animage.

The non-display area IA can be provided in the other portion except forthe display area AA provided on the substrate 100 and can be defined asan edge of the substrate 100 surrounding the display area AA. Thenon-display area IA can be a peripheral area outside the display area AAand may not display an image unlike the display area AA. Also, thenon-display area IA can include a bending area BA connected to thedriver 300.

The bending area BA can be an area disposed in the non-display area IAand can be an area where a routing wiring is disposed, which connectsthe driver 300 to the display area AA. The bending area BA can be anarea which is provided in order for a portion of the non-display area IAto be folded in one direction, and causes a reduction of the bezel areaof the organic light emitting display apparatus according embodiments ofthe present disclosure.

The driver 300 can be connected to a pad part provided in thenon-display area IA of the substrate 100 for displaying an image,corresponding to video data supplied from a display driving system, onthe display area AA. The driver 300 according to an embodiment caninclude a driving circuit 310 and can have a chip-on film (COF)structure. For example, the driver 300 can include a flexible film, adriving integrated circuit (IC) disposed on the flexible film, and aplurality of driving terminals disposed in one edge of the flexiblefilm.

The circuit board 400 can be electrically connected to the driver 300.The circuit board 400, according to an embodiment, can transfer signalsand power between elements of the driver 300. The circuit board 400 canbe a printed circuit board (PCB) having flexibility.

FIG. 2 is a cross-sectional view, taken along line I-I′ of FIG. 1, of anorganic light emitting display apparatus according to a first embodimentof the present disclosure.

Referring to FIG. 2, the organic light emitting display apparatusaccording to the present embodiment can include a substrate 100, abuffer layer 110, a pixel array layer, a planarization layer 150, alight emitting device layer 160, a plurality of banks 170A and 170B, aplurality of spacers 180A and 180B, an encapsulation layer 190, arouting wiring 161B, a coating layer 200, and a contact hole CH.

The substrate 100, e.g., a TFT array substrate, can be formed of glass,plastic, semiconductor and/or the like. The substrate 100 according toan embodiment can include a display area AA and a non-display area IA.

The buffer layer 110 can be provided in the display area AA of thesubstrate 100. The buffer layer 110 according to an embodiment preventswater or moisture from permeating into the pixel array layer. The bufferlayer 110 can be formed of an inorganic insulating material, and forexample, can be formed of silicon dioxide (SiO₂), silicon nitride(SiNx), or a multilayer thereof, but is not limited thereto.

The pixel array layer can be provided on the buffer layer 110. The pixelarray layer can include a thin film transistor T, a driving wiring 133,and an interlayer insulation layer 140.

The thin film transistor T can be provided on the buffer layer 110. Thethin film transistor T according to an embodiment can control the amountof current flowing from the driver 300 to the light emitting devicelayer 160. The thin film transistor T can include a semiconductor layer111, a gate electrode 121, a source electrode 131, and a drain electrode132.

The semiconductor layer 111 can be provided on the buffer layer 110. Thesemiconductor layer 111 can include a semiconductor material includingone of amorphous silicon, polycrystalline silicon, oxide material, andan organic material, but is not limited thereto.

The gate electrode 121 can be formed on a semiconductor insulation layer120 along with a gate line. The gate electrode 121 can be covered by agate insulation layer 130.

The source electrode 131 can be provided on one side of the gateinsulation layer 130 to overlap one side of the semiconductor layer 111.The source electrode 131 can be formed along with a data line and adriving power line.

The drain electrode 132 can be provided on the other side of the gateinsulation layer 130 to overlap the other side of the semiconductorlayer 111 and can be spaced apart from the source electrode 131. Thedrain electrode 132 can be formed along with the source electrode 131and can branch or protrude from an adjacent driving power line (or dataline).

The driving wiring 133 can include a gate line and a data line whichintersect each other to define a pixel. Also, the driving wiring 133 canfurther include a driving power line provided adjacent to the data line.

The gate line can be provided on the semiconductor insulation layer 120which is provided on the same layer as the gate electrode 121. That is,the semiconductor insulation layer 120 can be disposed between thesubstrate 100 and the gate line.

The data line or the driving power line, as illustrated in FIG. 2, maybe provided on the same layer as the source electrode 131 and the drainelectrode 132 on the gate insulation layer 130. That is, the gateinsulation layer 130 may be disposed between the gate line and the dataline.

The gate line according to an embodiment can be formed of the samematerial as that of the gate electrode 121, and the data line and thedriving power line can be formed of the same material as that of each ofthe source electrode 131 and the drain electrode 132. Therefore, thedriving wiring 133 can be formed of the same material as that of one ofor all of the gate electrode 121, the source electrode 131, and thedrain electrode 132.

The interlayer insulation layer 140 can be provided on the sourceelectrode 131, the drain electrode 132, and the driving wiring 133. Theinterlayer insulation layer 140 can insulate the thin film transistor Tfrom the outside and protect the thin film transistor T from a chemicalmaterial, water, and gases in a manufacturing process. The interlayerinsulation layer 140 can be formed of an inorganic material which is lowin conductive and flexible characteristics, or can be formed of aninorganic material including silicon (Si). The contact hole CHelectrically connecting the driving wiring 133 to the routing wiring161B can be provided in the interlayer insulation layer 140 according toan embodiment. A detailed structure thereof will be described below.

The planarization layer 150 can be provided on the substrate 100 tocover the pixel array layer. The planarization layer 150 protects thethin film transistor T and provides a planar surface on the thin filmtransistor T. The planarization layer 150 according to an embodiment canbe formed of an organic material, such as benzocyclobutene or photoacryl, but for convenience of a process, the planarization layer 150 canbe formed of a photo acryl material.

The planarization layer 150 according to an embodiment can be providedto contact the substrate 100 in the bending area BA. That is, theplanarization layer 150 can be provided in a whole region or entire areaof the substrate 100. Since the buffer layer 110 and the insulationlayers 120, 130, and 140 are not provided in the bending area BA of thesubstrate 100, according to an embodiment, the planarization layer 150can be provided to directly contact the substrate 100. When theplanarization layer 150 is formed of an organic insulating material, theplanarization layer 150 can have characteristics that a degree of damagecaused by stress, tension, or other external force acting in bendingprocess is small and the flexibility is high. Therefore, since theplanarization layer 150 is provided to contact the substrate 100 in thebending area BA of the substrate 100, the bending process of an organiclight emitting display apparatus can be more easily and safelyperformed.

The light emitting device layer 160 can be provided on the planarizationlayer 150. The light emitting device layer 160 according to anembodiment can include a first electrode 161A, a light emitting layer162, and a second electrode 163.

The first electrode 161A, an anode electrode, can be provided in apattern on the planarization layer 150. The first electrode 161Aaccording to an embodiment can be electrically connected to the sourceelectrode 131 of the thin film transistor T through a contact holeprovided in the planarization layer 150 and receive a data currentoutput from the thin film transistor T. The first electrode 161A can beformed of a metal material having the high reflectivity, and forexample, can include a material such as gold (Au), silver (Ag), aluminum(Al), molybdenum (Mo), or magnesium (Mg), or an alloy thereof, but isnot limited thereto.

The light emitting layer 162 can be provided on the first electrode 161Ain an opening area (or emission area) defined by a first bank 170A. Thelight emitting layer 162 according to an embodiment can include a holeinjection layer, a hole transport layer, an organic light emittinglayer, an electron transport layer, and an electron injection layerwhich are sequentially stacked on the first electrode 161A. Here, one ormore among the hole injection layer, the hole transport layer, theelectron transport layer, and the electron injection layer may beomitted. In addition, the light emitting layer 162 can further includeat least one function layer for controlling an electron and/or a holeinjected into the organic light emitting layer.

The second electrode 163 can be provided on the substrate 100 to coverthe light emitting layer 162 and the first bank 170A and can beconnected to all or some of the light emitting layers 162 formed overthe whole surface of the substrate 100 in common. The second electrode163 can be defined as a cathode electrode or a common electrode, basedon a direction of a current flowing in the light emitting layer 162. Thesecond electrode 163 can receive a cathode power supplied from thedriver 300. Here, the cathode power can be a ground voltage or a directcurrent (DC) voltage having a certain voltage level.

The second electrode 163 according to an embodiment can be formed of atransparent metal material having a high light transmittance. Forexample, the second electrode 163 can include indium tin oxide (ITO),indium zinc oxide (IZO), indium zinc tin oxide (IZTO), indium cesiumoxide (ICO), or indium tungsten oxide (IWO), which is a transparentconductive material such as transparent conductive oxide (TCO).Optionally, in the present embodiment, in order to minimize damage ofthe light emitting layer 162 caused by a process temperature in aprocess of forming the second electrode 163, the second electrode 163can be formed of an amorphous transparent conductive material through alow temperature metal deposition process using a process temperature ofless than 100 degrees Celsius. That is, in a situation that the secondelectrode 163 is formed of a crystalline transparent conductivematerial, there is a problem in which the light emitting layer 162 isdamaged by a high temperature thermal treatment process which isperformed on the second electrode 163 to ensure a low resistance value.Therefore, to address this issue, the second electrode 163 can be formedof the amorphous transparent conductive material by the low temperaturemetal deposition process.

The first bank 170A can be provided on the planarization layer 150 tocover an edge of the first electrode 161A and the thin film transistor Tand can define an opening area. The first bank 170A according to anembodiment can include an organic material such as benzocyclobutadiene,acryl, or polyimide. Additionally, the first bank 170A can be formed ofa photosensitive agent including a black pigment, and in this instance,the first bank 170A can act as a light blocking member (or a blackmatrix).

A first spacer 180A can be provided on the first bank 170A. The firstspacer 180A can be provided for preventing a dark spot defect fromoccurring when a mask contacts the first electrode 161A in a process ofdepositing the light emitting layer 162. The mask may have acharacteristic in which a center portion thereof sags, and a saggingportion may contact the first electrode 161A. The first spacer 180Aaccording to an embodiment can be provided on the first bank 170A andcan separate the sagging mask from the first electrode 161A by a certaindistance so the sagging mask does not touch the first electrode 161A.Therefore, since the mask does not contact the first electrode 161A, theoccurrence of a dark spot defect is prevented.

The encapsulation layer 190 can be provided on the light emitting layer162, for preventing permeation of water or gases to protect the lightemitting layer 162 vulnerable to external water or oxygen. That is, theencapsulation layer 190 can be provided in the display area AA and thenon-display area IA of the substrate 100 to cover the second electrode163. The encapsulation layer 190 according to an embodiment can beformed of an inorganic layer or an organic layer, or be formed in amulti-layer structure in which an inorganic layer and an organic layerare alternately stacked.

The encapsulation layer 190 can effectively prevent permeation ofexternal water, and thus, can completely seal a side surface of thedisplay area AA to protect the thin film transistor T and the lightemitting device layer 160 provided in the display area AA. Theencapsulation layer 190 according to an embodiment can be provided tocover a side surface of each of the first bank 170A and the first spacer180A adjacent to a wiring contact part CP. The first bank 170A and thefirst spacer 180A can be disposed on a side surface of the lightemitting device layer 160. Therefore, when the side surface of each ofthe first bank 170A and the first spacer 180A is externally exposed,external water and gases may reach the light emitting device layer 160via the first bank 170A and the first spacer 180A. Accordingly, toaddress this issue, the encapsulation layer 190 can seal the sidesurface of each of the first bank 170A and the first spacer 180A toprotect the light emitting device layer 160 from permeation of externalwater and gases.

The routing wiring 161B can be disposed in the bending area BA of thesubstrate 100. In more detail, the routing wiring 161B can be providedon the planarization layer 150 provided in the bending area BA. Therouting wiring 161B according to an embodiment can electrically connectthe driver 300 to the driving wiring 133 and be formed of a metal line.

The routing wiring 161B according to an embodiment can be formed of arectilinear metal wiring to have a fine pattern, based on an ultra-highdefinition (UHD) mode of the organic light emitting display apparatus.Since the routing wiring 161B should send a data signal to the drivingwiring 133 in a limited space, a wiring width and a wiring interval caneach be set to approximately 2 μm to 4 μm.

The routing wiring 161B can be formed of the same material as that ofthe first electrode 161A. The routing wiring 161B can be formed in aprocess of depositing the first electrode 161A. That is, the routingwiring 161B and the first electrode 161A can be formed on theplanarization layer 150 which is the same layer, and thus, can besimultaneously formed.

The routing wiring 161B, according to an embodiment the presentdisclosure, can be provided on the planarization layer 150 including anorganic material which is good in adhesive force, and thus, a separateadhesive layer may not be provided. In a situation that the routingwiring 161B is formed in a process of depositing the source/drainelectrode 131/132, an additional adhesive layer for strengthening anadhesive force between the substrate 100 and the routing wiring 161B canbe provided between the substrate 100 and the routing wiring 161B.However, since the routing wiring 161B, according to an embodiment ofthe present disclosure, is provided on the planarization layer 150, anadditional adhesive layer may be omitted, and thus, the number of masksis reduced in a manufacturing process.

A second bank 170B can be provided on the routing wiring 161B. Thesecond bank 170B according to an embodiment can be formed of the sameorganic material as that of the first bank 170A and can be patterned andformed in a deposition process of forming the first bank 170A. Thesecond bank 170B can be formed of a material for preventing permeationof water and can protect the routing wiring 161B from external water orparticles.

A second spacer 180B can be provided on the second bank 170B. The secondspacer 180B according to an embodiment can be formed of the samematerial as that of the first spacer 180A and be patterned and formed ina deposition process of forming the first spacer 180A. The second spacer180B, like the second bank 170B, can be formed of a material forpreventing permeation of water and can protect the routing wiring 161Bfrom external water or particles. Also, a neutral surface in the bendingarea BA can be adjusted by adjusting a thickness of the second spacer180B. The neutral surface is the central layer of the whole thickness inthe bending area BA.

The coating layer 200 can be provided in a whole surface or the entirearea of the bending area BA of the substrate 100 to cover the secondspacer 180B. The coating layer 200 according to an embodiment can beformed of a photocurable resin and can be coated on target areas of theorganic light emitting display apparatus, according to embodiments ofthe present disclosure. In this regard, the coating layer 200 can becoated on the whole surface of the bending area BA.

The coating layer 200 according to an embodiment can be coated to have apredetermined thickness, to adjust a neutral surface of a portion whichis provided in the bending area BA of the substrate 100 in the organiclight emitting display apparatus according to the present embodiment. Inmore detail, the neutral surface in the bending area BA of the organiclight emitting display apparatus can be adjusted by the coating layer200 so that the neutral surface can be set on the routing wiring 161B.

The contact hole CH can be provided in the interlayer insulation layer140 and/or the planarization layer 150. The driving wiring 133 can beelectrically connected to the routing wiring 161B through the contacthole CH. Since the interlayer insulation layer 140 and the planarizationlayer 150 are formed to cover the driving wiring 133, the contact holeCH can be provided in order for the routing wiring 161B to beelectrically connected to the driving wiring 133. The contact hole CHcan be formed by removing the interlayer insulation layer 140 and theplanarization layer 150 overlapping a portion of the routing wiring 161Bthrough a hole patterning process using a photolithography processand/or an etching process.

The organic light emitting display apparatus, according to an embodimentof the present disclosure, can include a wiring contact part CP.

The wiring contact part CP can be provided in a portion of the displayarea AA and can be an area where the driving wiring 133 is electricallyconnected to the routing wiring 161B. That is, the wiring contact partCP can be an area including the contact hole CH.

The contact hole CH can be provided by removing the interlayerinsulation layer 140 and the planarization layer 150 overlapping aportion of the routing wiring 161B. The routing wiring 161B can beelectrically connected to the driving wiring 133 through the contacthole CH. In more detail, one side of the routing wiring 161B can beprovided to directly contact an upper surface of the planarization layer150 disposed to the left of the contact hole CH, and the other side ofthe routing wiring 161B can be provided to directly contact an uppersurface of the planarization layer 150 disposed to the right of thecontact hole CH. Therefore, the routing wiring 161B can be electricallyconnected to the driving wiring 133 through the contact hole CH.

Here, the planarization layer 150 disposed to the left side of thecontact hole CH can be a planarization layer 150 provided in the wiringcontact part CP, and the planarization layer 150 disposed to the rightside of the contact hole CH can be a planarization layer 150 provided inthe bending area BA.

As described above, in the organic light emitting display apparatus,according to an embodiment of the present disclosure, the routing wiring161B can be electrically connected to the driving wiring 133 through thecontact hole CH, and thus, the bending process can be easily and safelyperformed. In more detail, in a structure of the related art, since thedriving wiring 133 is formed to extend up to the driver 300, a crack mayeasily occur in the driving wiring 133 disposed in the bending area BA,and a short circuit may easily occur. Further, in the organic lightemitting display apparatus according to an embodiment of the presentdisclosure, since the driving wiring 133 does not extend to the bendingarea BA (e.g., driving wiring 133 terminates before an edge of thebending area BA) and the routing wiring 161B is separately provided onthe planarization layer 150 including an organic insulating material, adegree of damage caused by stress, tension, or other external forceapplied to the routing wiring 161B in the bending area BA is reduced.Accordingly, the bending process may be easily and safely performed.

Referring again to FIG. 2, the encapsulation layer 190 can be providedto cover the wiring contact part CP. That is, the encapsulation layer190 can be provided to cover the contact hole CH and prevent permeationof external water and particles. The contact hole CH can be formed byetching the planarization layer 150, and thus, the driving wiring 133and the thin film transistor T can be easily exposed at the outside bythe contact hole CH. Therefore, in the organic light emitting displayapparatus according to an embodiment of the present disclosure, theencapsulation layer 190 can be formed to seal the contact hole CH andthe wiring contact part CP including the contact hole CH, and thus, thethin film transistor T can be protected from permeation of externalwater.

FIG. 3 is a cross-sectional view, taken along line I-I′ of FIG. 1, of anorganic light emitting display apparatus according to a secondembodiment of the present disclosure. Referring to FIG. 3, except for awiring contact part CP, the organic light emitting display apparatusaccording to the second embodiment of the present disclosure has thesame configuration as that of the organic light emitting displayapparatus according to the first embodiment of the present disclosure.Therefore, the same description may not be duplicated, and a modifiedconfiguration of a wiring contact part will be described below.

Referring to FIG. 3, the organic light emitting display apparatusaccording to the present embodiment can include a planarization layer150 and an encapsulation layer 190.

The planarization layer 150 can be provided on a whole region or entirearea of the substrate 100, except not in a wiring contact part CP of thesubstrate 100. That is, the planarization layer 150 can be provided in aplurality of portions, and adjacent planarization layers 150 (e.g.,adjacent portions of the planarization layer 150) can be spaced apartfrom each other with the wiring contact part CP disposed therebetween.Since the planarization layer 150 is not formed in the wiring contactpart CP, the contact hole CH can be formed by removing an interlayerinsulation layer 140 overlapping a portion of a routing wiring 161Bthrough a hole patterning process using a photolithography process andan etching process.

Since the planarization layer 150 according to an embodiment is formedof an organic material, it is relatively difficult to etch theplanarization layer 150 in comparison with an inorganic material, and asize of the contact hole CH increases (e.g., contact hole CH is widerwhen having to etch through the planarization layer 150). However, inthe organic light emitting display apparatus according to the secondembodiment of the present disclosure, since the planarization layer 150is not formed in the wiring contact part CP, the contact hole CH can beformed by etching the interlayer insulation layer 140 including aninorganic material. Therefore, a process of forming the contact hole CHcan be relatively easy, and a size of the contact hole CH can bereduced. In other words, since the interlayer insulation layer 140 iseasier to etch, the contact hole CH can be made smaller. Accordingly, anaperture ratio is enhanced.

The routing wiring 161B can be electrically connected to the drivingwiring 133 through the contact hole CH. In more detail, one side of therouting wiring 161B can be provided to directly contact an upper surfaceof the interlayer insulation layer 140 disposed to the left side of thecontact hole CH, and the other side of the routing wiring 161B can beprovided to directly contact an upper surface of the planarization layer150 disposed to the right side of the contact hole CH. Therefore, therouting wiring 161B can be electrically connected to the driving wiring133 through the contact hole CH.

Here, the interlayer insulation layer 140 disposed to the left side ofthe contact hole CH can be an interlayer insulation layer 140 providedin the wiring contact part CP, and the planarization layer 150 disposedto the right side of the contact hole CH can be a planarization layer150 provided in the bending area BA.

The encapsulation layer 190 may be provided to cover a side surface ofthe planarization layer 150 adjacent to the wiring contact part CP. Theplanarization layer 150 can be provided to cover a thin film transistorT, and thus, when the side surface of the planarization layer 150 isexternally exposed, external water reaches the thin film transistor Tvia the planarization layer 150. Accordingly, the encapsulation layer190 according to an embodiment of the present disclosure can seal theside surface of the planarization layer 150 to protect the thin filmtransistor T from penetration of external water.

FIG. 4 is an enlarged view of a structure of a bending area in anorganic light emitting display apparatus according to an embodiment ofthe present disclosure.

Referring to FIG. 4, a neutral surface NP can be disposed in a routingwiring 161B (e.g., a conceptual plane or interface between a zone thatis in compression and a zone that is in tension, where there is minimalor no lengthwise stress force on the neutral plane).

As a substrate 100 is bent, one side can be stretched, and the otherside can be contracted, with respect to a specific surface. In thisinstance, the neutral surface NP can denote a surface which is providedin a center portion and has no contractility. Here, the neutral surfaceNP can denote a neutral surface of a portion which is provided in abending area BA of the substrate 100 in the organic light emittingdisplay apparatus according to the present embodiment. For example, therouting wiring 161B can be disposed on or near the area where a neutralsurface exists in order to minimize stress on the routing wiring 161B.

In the organic light emitting display apparatus according to the presentembodiment, the neutral surface NP can be adjusted through an organiclayer provided in the bending area BA (e.g., the location of where theneutral surface NP exists can be changed based on how thick the coatinglayer 200 is made). For example, as a coating layer 200 is thicklycoated, the neutral surface NP can be raised to an upper portion of thesubstrate 100 and can be located on the routing wiring 161B. Also, asecond spacer 180B can be provided in the bending area BA, and thus, theneutral surface NP can be raised based on an influence of a thickness ofthe second spacer 180B, whereby the neutral surface NP can be located ina region, which is vulnerable to a stress, of the routing wiring 161B.

When the neutral surface NP is located in the routing wiring 161B, abending stress applied to the routing wiring 161B is minimized, andthus, a stress is minimized. Also, a crack does not occur in maximumbending, and thus, the bending process of the organic light emittingdisplay apparatus may be easily and safely performed. In other words,the routing wiring 161B is arranged so that it exists in the neutralsurface when the substrate is bent (e.g., the safest place or area thatexperiences the least amount of bending stress).

As described above, the organic light emitting display apparatusaccording to the embodiments of the present disclosure enables bendingto be easily performed and effectively protects a light emitting devicefrom penetration of external water.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present disclosurewithout departing from the spirit or scope of the disclosures. Thus, itis intended that the present disclosure covers the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. An organic light emitting display apparatuscomprising: a substrate including a display area and a bending area; apixel array layer including a driving wiring in the display area, and athin film transistor electrically connected to the driving wiring; aplanarization layer covering the pixel array layer, a light emittingdevice layer disposed on the planarization layer, the light emittingdevice layer being electrically connected to the thin film transistor, arouting wiring disposed in the bending area, the routing wiring beingelectrically connected to the driving wiring; a wiring contact partincluding a contact hole for electrically connecting the driving wiringto the routing wiring; an encapsulation layer covering the lightemitting device layer and the wiring contact part; a first bank disposedbetween the planarization layer and the encapsulation layer to define anemission area in the display area; a second bank disposed on the routingwiring in the bending area; a first spacer disposed between the firstbank and the encapsulation layer; and a second spacer disposed on thesecond bank, wherein the encapsulation layer covers a side surface ofthe first bank adjacent to the wiring contact part, wherein theencapsulation layer covers a side surface of the first spacer adjacentto the wiring contact part, and wherein the encapsulation layer fills aportion of the contact hole above the routing wiring and terminatesbefore an edge of the bending area.
 2. The organic light emittingdisplay apparatus of claim 1, wherein the routing wiring directlycontacts the driving wiring in the contact hole of the wiring contactpart.
 3. The organic light emitting display apparatus of claim 1,wherein the light emitting device layer comprises: a first electrodedisposed on the planarization layer, the first electrode beingelectrically connected to the thin film transistor; a light emittinglayer disposed on the first electrode; and a second electrode disposedon the light emitting layer, wherein the routing wiring and the firstelectrode both comprise a same material.
 4. The organic light emittingdisplay apparatus of claim 1, wherein the planarization layer isadditionally disposed in the bending area, and wherein the routingwiring is disposed on the planarization layer in the bending area. 5.The organic light emitting display apparatus of claim 4, furthercomprising: an interlayer insulation layer covering the driving wiring,wherein the contact hole extends through the interlayer insulationlayer.
 6. The organic light emitting display apparatus of claim 5,wherein one side of the routing wiring directly contacts an uppersurface of the planarization layer in the wiring contact part, andwherein another side of the routing wiring directly contacts an uppersurface of the planarization layer in the bending area.
 7. The organiclight emitting display apparatus of claim 5, wherein one side of therouting wiring directly contacts an upper surface of the interlayerinsulation layer, and wherein another side of the routing wiringdirectly contacts an upper surface of the planarization layer in thebending area.
 8. The organic light emitting display apparatus of claim1, further comprising: a coating layer disposed on the second spacer. 9.The organic light emitting display apparatus of claim 8, wherein aneutral surface of the bending area is disposed in the routing wiring.10. The organic light emitting display apparatus of claim 9, wherein athickness of the coating layer is configured to adjust the neutralsurface of the bending area to be centered on the routing wiring forreducing stress on the routing wiring.
 11. The organic light emittingdisplay apparatus of claim 1, wherein the muting wiring directlycontacts an upper surface of the planarization layer on opposite sidesof the contact hole in the wiring contact part.
 12. The organic lightemitting display apparatus of claim 1, further comprising: an interlayerinsulation layer disposed on the driving wiring, wherein the contacthole extends through the interlayer insulation layer, and wherein therouting wiring directly contacts an upper surface of the interlayerinsulation layer on opposite sides of the contact hole in the wiringcontact part.
 13. The organic light emitting display apparatus of claim1, wherein a lowermost surface of the planarization layer directlycontacts an uppermost surface of the substrate in the bending area,wherein a side surface of the planarization layer directly contacts therouting wiring in the bending area, and wherein an uppermost surface ofthe planarization layer directly contacts a lower surface of the routingwiring in the bending area.
 14. The organic light emitting displayapparatus of claim 1, wherein the planarization layer is absent from thewiring contact part, and wherein the encapsulation layer overlaps withthe routing wiring in the contact part.
 15. An organic light emittingdisplay apparatus comprising: a substrate including a display area and abending area; a driving wiring in the display area and a thin filmtransistor electrically connected to the driving wiring; a planarizationlayer disposed in the display area; a routing wiring disposed in thebending area, the routing wiring being electrically connected to thedriving wiring; a wiring contact part including a contact hole forelectrically connecting the driving wiring to the routing wiring; anencapsulation layer covering the display area and the wiring contactpart; a first bank disposed between the planarization layer and theencapsulation layer to define an emission area in the display area; asecond bank disposed on the routing wiring in the bending area; a firstspacer disposed between the first bank and the encapsulation layer; anda second spacer disposed on the second bank, wherein a portion of theplanarization layer is disposed between the routing wiring and thesubstrate in the bending area, wherein the encapsulation layer covers aside surface of the first bank adjacent to the wiring contact part,wherein the encapsulation layer covers a side surface of the firstspacer adjacent to the wiring contact part, and wherein theencapsulation layer fills a portion of the contact hole above therouting wiring and terminates before an edge of the bending area. 16.The organic light emitting display apparatus of claim 15, wherein anupper surface of the portion of the planarization layer directlycontacts a lower surface of the routing wiring in the bending area, andwherein a lower surface of the portion of the planarization layerdirectly contacts an upper surface of the substrate in the bending area.17. The organic light emitting display apparatus of claim 15, whereinthe routing wiring is disposed on opposite sides of the contact hole inthe wiring contact part.
 18. An organic light emitting display apparatuscomprising: a substrate including a display area and a bending area; apixel array layer including a driving wiring in the display area, and athin film transistor electrically connected to the driving wiring; aplanarization layer disposed on the pixel array layer; a light emittingdevice layer disposed on the planarization layer, the light emittingdevice layer being electrically connected to the thin film transistor; arouting wiring disposed in the bending area, the routing wiring beingelectrically connected to the driving wiring; a contact hole forelectrically connecting the driving wiring to the routing wiring; anencapsulation layer covering the light emitting device layer; a firstbank disposed between the planarization layer and the encapsulationlayer to define an emission area in the display area; a second bankdisposed on the routing wiring in the bending area; a first spacerdisposed between the first bank and the encapsulation layer; and asecond spacer disposed on the second bank, wherein a portion of theplanarization layer is disposed between the routing wiring and thesubstrate in the bending area, wherein a side surface of the portion ofthe planarization layer directly contacts the routing wiring, whereinthe encapsulation layer covers a side surface of the first bank adjacentto the wiring contact part, wherein the encapsulation layer covers aside surface of the first spacer adjacent to the wiring contact part,and wherein the encapsulation layer fills a portion of the contact holeabove the routing wiring and terminates before an edge of the bendingarea.
 19. The organic light emitting display apparatus of claim 8,wherein the coating layer directly contacts the encapsulation layer. 20.The organic light emitting display apparatus of claim 8, wherein theencapsulation layer completely fills the contact hole above the routingwiring.